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Diffstat (limited to '')
-rw-r--r-- | fs/afs/xdr_fs.h | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/fs/afs/xdr_fs.h b/fs/afs/xdr_fs.h new file mode 100644 index 000000000..8ca868164 --- /dev/null +++ b/fs/afs/xdr_fs.h @@ -0,0 +1,116 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* AFS fileserver XDR types + * + * Copyright (C) 2018 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#ifndef XDR_FS_H +#define XDR_FS_H + +struct afs_xdr_AFSFetchStatus { + __be32 if_version; +#define AFS_FSTATUS_VERSION 1 + __be32 type; + __be32 nlink; + __be32 size_lo; + __be32 data_version_lo; + __be32 author; + __be32 owner; + __be32 caller_access; + __be32 anon_access; + __be32 mode; + __be32 parent_vnode; + __be32 parent_unique; + __be32 seg_size; + __be32 mtime_client; + __be32 mtime_server; + __be32 group; + __be32 sync_counter; + __be32 data_version_hi; + __be32 lock_count; + __be32 size_hi; + __be32 abort_code; +} __packed; + +#define AFS_DIR_HASHTBL_SIZE 128 +#define AFS_DIR_DIRENT_SIZE 32 +#define AFS_DIR_SLOTS_PER_BLOCK 64 +#define AFS_DIR_BLOCK_SIZE 2048 +#define AFS_DIR_BLOCKS_PER_PAGE (PAGE_SIZE / AFS_DIR_BLOCK_SIZE) +#define AFS_DIR_MAX_SLOTS 65536 +#define AFS_DIR_BLOCKS_WITH_CTR 128 +#define AFS_DIR_MAX_BLOCKS 1023 +#define AFS_DIR_RESV_BLOCKS 1 +#define AFS_DIR_RESV_BLOCKS0 13 + +/* + * Directory entry structure. + */ +union afs_xdr_dirent { + struct { + u8 valid; + u8 unused[1]; + __be16 hash_next; + __be32 vnode; + __be32 unique; + u8 name[]; + /* When determining the number of dirent slots needed to + * represent a directory entry, name should be assumed to be 16 + * bytes, due to a now-standardised (mis)calculation, but it is + * in fact 20 bytes in size. afs_dir_calc_slots() should be + * used for this. + * + * For names longer than (16 or) 20 bytes, extra slots should + * be annexed to this one using the extended_name format. + */ + } u; + u8 extended_name[32]; +} __packed; + +/* + * Directory block header (one at the beginning of every 2048-byte block). + */ +struct afs_xdr_dir_hdr { + __be16 npages; + __be16 magic; +#define AFS_DIR_MAGIC htons(1234) + u8 reserved; + u8 bitmap[8]; + u8 pad[19]; +} __packed; + +/* + * Directory block layout + */ +union afs_xdr_dir_block { + struct afs_xdr_dir_hdr hdr; + + struct { + struct afs_xdr_dir_hdr hdr; + u8 alloc_ctrs[AFS_DIR_MAX_BLOCKS]; + __be16 hashtable[AFS_DIR_HASHTBL_SIZE]; + } meta; + + union afs_xdr_dirent dirents[AFS_DIR_SLOTS_PER_BLOCK]; +} __packed; + +/* + * Directory layout on a linux VM page. + */ +struct afs_xdr_dir_page { + union afs_xdr_dir_block blocks[AFS_DIR_BLOCKS_PER_PAGE]; +}; + +/* + * Calculate the number of dirent slots required for any given name length. + * The calculation is made assuming the part of the name in the first slot is + * 16 bytes, rather than 20, but this miscalculation is now standardised. + */ +static inline unsigned int afs_dir_calc_slots(size_t name_len) +{ + name_len++; /* NUL-terminated */ + return 1 + ((name_len + 15) / AFS_DIR_DIRENT_SIZE); +} + +#endif /* XDR_FS_H */ |